Massport raised concerns about tower in Dec. 2016

Massport raised concerns about tower in Dec. 2016

Higher than 710 feet is a problem, letter says

The following is a December 22, 2016, letter from Stewart Dalzell, Massport’s deputy director of environmental planning and permitting, to Matthew Beaton, the state secretary of energy and environmental affairs, regarding the proposed tower from Millennium Partners at 115 Winthrop Square.

Dear Secretary Beaton:

On behalf of the Massachusetts Port Authority (Massport), thank you for the opportunity to submit comments on the Environmental Notification Form (ENF) filing for the 115 Winthrop Square Project. The Project seeks to build a 775 foot tall, 1.1-1.5 million sf mixed use building at 115 Winthrop Square in Boston.  As stated in the ENF, the project exceeds a mandatory Environmental Impact Review (EIR) threshold and thus comments on this filing will be used in the development of the Draft EIR Scope.

Massport supports new development projects that strengthen our economy and provide employment opportunities to its residents. Our main aviation priority is to ensure aircraft are able to operate in a safe and efficient manner in and around Logan Airport.  In that context, Massport strongly objects to the proposed tower height of 775 feet at the 115 Winthrop Square site. The proposed tower exceeds the height limit of 710 feet above mean sea level (AMSL) as defined by the Boston- Logan International Airport Composite Map of Critical Airspace Surfaces (Logan Airspace Map, attached).  Note that the 710 AMSL limit will apply to the tallest point(s) of the proposed structure above sea level including mechanical units, antennas, etc.  We have had initial discussions with the proponent and expect to continue the dialogue.

A building height greater than 710 feet MSL at the 115 Winthrop Square location would have the following impacts on Logan Airport operations:

  • Significantly impact Runway 27 Departures. The proposed structure will penetrate the Federal Aviation Administration’s (FAA) existing Runway 27 departure corridor. A building taller than 710’ AMSL at this location would significantly reduce the capacity of the remaining airspace.
  • Lead airlines to shift departures from Runway 27 to Runway 33L. This would reduce the efficiency of flight departure configurations in a Northwest wind condition
  • Shift overflights and associated noise from communities south of Boston to communities west and north of Boston
  • Restrict existing FAA Circle-to-Land operations to all runways, reducing flexibility of Logan FAA Air Traffic Control Tower to manage close-in flights

Therefore, Massport urges MCAF Winthrop LLC to explore alternative designs that meet the same project goals without exceeding the height of the 710 feet AMSL that would cause significant adverse Logan Airport operational and noise impacts. 

About the Logan Airspace Map

The Logan Airspace Map defines the critical airspace around Boston Logan International Airport to protect the flight corridors in and out of the airport. It was created by Massport with input from airlines, pilots, city officials, and the Federal Aviation Administration (FAA) to help guide developers and regulatory authorities on building heights. The map aids developers in their planning and assists the FAA in its review of individual projects to determine if they present a potential hazard to air navigation. It was widely distributed to among the development agencies including BPDA and the developer communities and is available at: Note that the Logan Air Space Map is based on the NAVD 88 datum and is different from Boston City Base Datum.

Massport is committed to collaborating with the MCAF Winthrop LLC to ensure that the Project complies with the Airspace Map and can be completed in a timely manner. Massport will work with the Proponent from the beginning of the design and permitting process and during construction to minimize the impact of the cranes on Logan airspace.

Complying with the Airspace Map does not relieve proponents of the responsibility of complying with the FAA 7460 review process. MCAF Winthrop LLC will be required to file the 7460 forms no later than 45 days prior to construction but we encourage that this be filed as early as possible to avoid delays. Separate forms have to be filed for the building and the construction cranes.

Thank you for your consideration of our comments. Please feel free to contact me at (617) 568-3524 or at if you wish to discuss any of our concerns.


Massachusetts Port Authority

Stewart Dalzell, Deputy Director

Environmental Planning and Permitting

Cc:       T. Glynn, E. Freni, J. Doolin, J. Pranckevicius, H. Morrison, F. Leo, S. Gongal/Massport

  1. Walsh/FAA
  2. Larkin/Millennium Partners
  3. Tracy/BPDA
  4. Schlessinger/Epsilon Associates